Posted: 6/1/2014 6:25:17 AM EDT
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"Mark", they said, "why 3 shot groups when some online rifle lovers have "locked on" to the idea that only a 5 shot group, or 10 shot groups or 20 shot groups are of consequence ?"
Here's the answer - Damn few "production" rifles come with a proof-group - ours does. Shooting a 3-shot group takes x amount of time to do ... if we shot 5-shot groups, it would damn near double our proof-grouping cycle time ... 10-shot groups would triple that cycle time. Then there's operator fatigue. Until you've hauled a daily mess of 7.62 rifles to a our range out back, with me breathing down your back to improve cycle times, you don't know how much you'll hate shooting. Though we're thinking about adding a 2nd underground tunnel, it's not so we can shoot more bullets per groups, it's so we can group more rifles per day. Having shot a gazillion groups since we decided to make barrels in-house, and given the reason we decided to make barrels in-house was so we would know exactly what occurred during each barrel's creation (process control), we've got our process under control and if you've seen one, you've almost seen 'em all. Here's some posts I've thrown up on the board here of late ... Okay, it's Friday and I dug out their best-of-the-day target and added it to the other four B-O-T-D targets  to round out this week.
I just might make this a regular thing ... 
ETA - 100 yards - Factory ammo - FGMM 77 gr. 
ETA - Here's a pic of the smallest half-dozen rifles proof-grouped today. 
Below is May, 5th, 6th, 7th, 8th, and 9th - interesting that the small-group average from this week is within a thousandths or two of last weeks. 
Tossed in 2 from Friday - a small boolitt and a big boolitt ... 
And here's that .164" ... 
I dug through the pile of PredatAR 7.62s proof-grouped yesterday ...and grabbed out what looked like the smallest ... In the interest of full-disclosure, these are the best of the day I dug out - the ones I left in the pile shot bigger than this - but they are all made using the same process - seem to be averaging around .7 moa - that means that some shot .9-something and others shot .2-something yada yada. This explanation is due to threats from a customer that wrote we better not stop shipping him replacement rifles until he received one that out-flinched his flinching into shooting under a half minute all the time. Yes, I added the term flinching because I'm a bit of an azz. 
4-Day work week ... Tuesday - Friday 
We know what our barrel process normally produces and we shoot quick just to verify something didn't slip through the QC Dragnet. He's not back there trying his absolute damndest to squeeze everything out of the rifle. I recently took one of 'em out back to prove a point in the 1 MOA All Day thread ... shot it fast, real fast, and got this ... Quoted:
<snip> As you ordered ... so, because it had not been shipped to the customer yet, I grabbed the stock rifle that shot the far-right group = .265" on Friday of last week, it hadn't gone out yet (waiting on a lower) ...
.. and took it out back and shot the Challenge sorta fast with it ... 1 to 2 seconds between shots. The Lowe's kid has young eyes  ... and I added the grid cause I like grids. 
I took a pic to show the setup, sure that I busted some of the 1 MOA Challenge regs. 
ETA - That's a 16" LaRue PredatOBR, the barrel was made from scratch in our in-house barrel shop. Checkmate. Be advised, we make the barrels that go into our UHFO Stealth uppers using the same process used on all the above rifles. And yes, this is the June Until Hell Freezes Over thread you seek. GO ! "Gundrilling at LaRue" 
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I don't know what all this horseshit is about but 3 shot groups are meaningless, I have gotten many great five shot groups during load development but the load wouldn't repeat under different conditions, it was unstable and a lucky occurrence at the time. More shots in the group over multiple groups tell the true story of the load, gun and shooter. Obviously your barrels worked well for your conditions over three shots but that is all that tells me.
I wouldn't however expect a manufacturer to provide endless numbers of groups, if you are providing these as a selling point it would be just a waste of you time. |